ASoC: sta350: Add codec driver

The TI STA350 is an integrated 2.1-channel power amplifier that is
controllable over I2C. This patch adds an ASoC driver for it.

At a glance, this chip is very similar to the STA320 for which a driver
already exists. In details, however, the register maps contain subtle
differences which made a whole new driver easier to write and maintain.

[daniel@zonque.org: cleanups, DT property rework, rebased on asoc-next]
Signed-off-by: Sven Brandau <brandau@gmx.de>
Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sound/st,sta350.txt b/Documentation/devicetree/bindings/sound/st,sta350.txt
new file mode 100644
index 000000000000..950188891abd
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/st,sta350.txt
@@ -0,0 +1,107 @@
+STA350 audio CODEC
+
+The driver for this device only supports I2C.
+
+Required properties:
+
+  - compatible: "st,sta350"
+  - reg: the I2C address of the device for I2C
+  - reset-gpios: a GPIO spec for the reset pin. If specified, it will be
+		 deasserted before communication to the codec starts.
+
+  - power-down-gpios: a GPIO spec for the power down pin. If specified,
+		      it will be deasserted before communication to the codec
+		      starts.
+
+  - vdd-dig-supply: regulator spec, providing 3.3V
+  - vdd-pll-supply: regulator spec, providing 3.3V
+  - vcc-supply: regulator spec, providing 5V - 26V
+
+Optional properties:
+
+  -  st,output-conf: number, Selects the output configuration:
+	0: 2-channel (full-bridge) power, 2-channel data-out
+	1: 2 (half-bridge). 1 (full-bridge) on-board power
+	2: 2 Channel (Full-Bridge) Power, 1 Channel FFX
+	3: 1 Channel Mono-Parallel
+	If parameter is missing, mode 0 will be enabled.
+
+  -  st,ch1-output-mapping: Channel 1 output mapping
+  -  st,ch2-output-mapping: Channel 2 output mapping
+  -  st,ch3-output-mapping: Channel 3 output mapping
+	0: Channel 1
+	1: Channel 2
+	2: Channel 3
+	If parameter is missing, channel 1 is choosen.
+
+  -  st,thermal-warning-recover:
+	If present, thermal warning recovery is enabled.
+
+  -  st,thermal-warning-adjustment:
+	If present, thermal warning adjustment is enabled.
+
+  -  st,fault-detect-recovery:
+	If present, then fault recovery will be enabled.
+
+  -  st,ffx-power-output-mode: string
+	The FFX power output mode selects how the FFX output timing is
+	configured. Must be one of these values:
+	  -  "drop-compensation"
+	  -  "tapered-compensation"
+	  -  "full-power-mode"
+	  -  "variable-drop-compensation" (default)
+
+  -  st,drop-compensation-ns: number
+	Only required for "st,ffx-power-output-mode" ==
+	"variable-drop-compensation".
+	Specifies the drop compensation in nanoseconds.
+	The value must be in the range of 0..300, and only
+	multiples of 20 are allowed. Default is 140ns.
+
+  -  st,overcurrent-warning-adjustment:
+	If present, overcurrent warning adjustment is enabled.
+
+  -  st,max-power-use-mpcc:
+	If present, then MPCC bits are used for MPC coefficients,
+	otherwise standard MPC coefficients are used.
+
+  -  st,max-power-corr:
+	If present, power bridge correction for THD reduction near maximum
+	power output is enabled.
+
+  -  st,am-reduction-mode:
+	If present, FFX mode runs in AM reduction mode, otherwise normal
+	FFX mode is used.
+
+  -  st,odd-pwm-speed-mode:
+	If present, PWM speed mode run on odd speed mode (341.3 kHz) on all
+	channels. If not present, normal PWM spped mode (384 kHz) will be used.
+
+  -  st,distortion-compensation:
+	If present, distortion compensation variable uses DCC coefficient.
+	If not present, preset DC coefficient is used.
+
+  -  st,invalid-input-detect-mute:
+	If not present, automatic invalid input detect mute is enabled.
+
+
+
+Example:
+
+codec: sta350@38 {
+	compatible = "st,sta350";
+	reg = <0x1c>;
+	reset-gpios = <&gpio1 19 0>;
+	power-down-gpios = <&gpio1 16 0>;
+	st,output-conf = <0x3>;			// set output to 2-channel
+						// (full-bridge) power,
+						// 2-channel data-out
+	st,ch1-output-mapping = <0>;		// set channel 1 output ch 1
+	st,ch2-output-mapping = <0>;		// set channel 2 output ch 1
+	st,ch3-output-mapping = <0>;		// set channel 3 output ch 1
+	st,max-power-correction;		// enables power bridge
+						// correction for THD reduction
+						// near maximum power output
+	st,invalid-input-detect-mute;		// mute if no valid digital
+						// audio signal is provided.
+};